More research is needed. I still have a contact at Dolby Labs, and at H/K, so I'll send off an email and see what comes back. I think I read about this in a thread on another forum.

There will be an update. . .

Thanks for taking an interest in this, I’m very curious as to what’s happening so I hope you come up with something.

Originally Posted By: EFalardeau

That could be an indication (if the difference is THAT big), that your sub-woofer might be configured too "hot" to match your mains only.

I was thinking the same thing which is why when I ran my test I reset all crossovers to 80Hz (had my mains set to 60Hz) in both 2ch direct + subwoofer and multi-channel. I also reset all the speakers to the base calibration so nothing was running hot.

To reiterate when I switch between 2ch direct + sub and DPLllx music the overall SPL at the listening position stays the same but the subwoofer‘s output goes up 8-10dB in DPLllx music, in DPLllx cinema there is an overall increase of about 2dB at the listening position. There’s a corresponding drop from the main’s woofers.

Originally Posted By: kcarlile

I knew there was a reason I exclusively use Neo6.

I Just tested Neo6 and it’s doing the same thing only it’s upping the subwoofer by 10-12 dB vs Dolby’s 8-10 but just like Dolby the overall SPL is staying the same.

Now what I always do when I'm calibrating DD or DTS (non-Neo6 or PLII) is calibrate the sub 10 dB hotter than the mains. However, that could be an artifact of my calibration disc: the original non-Avia one, whatever that is.

I assume my settings from the DD and DTS carry over to PLII and Neo6, respectively. I could be horribly wrong, of course.

Okay, I punched up the Rachmaninoff 1st Symphony, which has a quite bass-heavy passage about 25 seconds in. I switched between the DPLII Music and Movie modes several times each at the point and measured no significant difference(12" from EP500)with my SPL meter. The Movie mode averaged about a dB higher, but that could simply be measurement error.

Edit: I took more time and ran the same several times each with straight stereo, Neo:6 and Neural Surround(don't have Logic 7 available). All measurements were essentially identical within a dB.